Photographic products and processes using alkali permeable polymeric layers



Dec. 18, 1962 I H. c. HAAS PHOTOGRAPHIC PRODUCTS AND PROCESSES USING 3,069,263

ALKALI PERMEABLE POLYMERIC LAYERS Filed Dec. 17, 1958 SILVER HALIDE EMULSION LAYER l2 N-METHYLACRYLAMIDE-N-METHYLOLACRYLAMIDE COPOLYMER LAYER CONTAINING A coLoR lo WW PROVIDING SUBSTANCE /\SUPPORT F l G. l

BLUE-SENSITIVE SILVER HALIDE EMULSION LAYER f fvh tfivf- 'EbYY EiYKhRE T 36 YELLOW DYE DEVELOPER 34- INTERLAYER 32 GREEN-SENSITIVE SILVER HALIDE so MULSION LAYER N-METHYLACRYLAMIDE-N-METHYLOLAGRYLAMIDE 2e COPOLYMER LAYER CONTAINING A 26 {MAGENTA DYE DEVELOPER 24- 'NTERLAYER 22 \fiiso-seNsmvs SILVER HALIDE EMULSION LAYE N- METHYLACRYLAMIDE-N-METHYLOIJACRYLAMIDE COPOLYMER LAYER CONTAINING A CYAN DYE DEVELOPER SUPPORT I gVENiOR.

? ATTSRNEYs is exposed to create therein a latent image.

United States Patent ()fiee 3,069,263 Patented Dec. 18, 1962 3,069,263 PHOTOGRAPHIC PRODUCTS AND PROCESSES USING ALKALI PERMEABLE POLYMERIC LAYERS Howard C. Haas, Arlington, Mass., assignor to Polaroid Corporation, Cambridge, Mass., a corporation of Delaare Filed Dec. 17, 1958, Ser. No. 780,979 17 Claims. (Cl. 96-29) The present invention is concerned with photography and more particularly with novel photographic products and novel photographic processes utilizing said products.

One object of the present invention is to provide novel photosensitive elements for color diffusion transfer processes comprising at least one silver halide emulsion layer and at least one polymeric layer having a color-providing substance disposed therein; said polymeric layer comprising (A) polymers of N-alkyl-u,B-unsaturated carboxamides and (B) copolymers of N-alkyl-a, 3-unsaturated carboxamides with N-hydroxyalkyl-oz,fi-unsaturated carboxamides.

' Another object of the present invention is to provide improved color diffusion transfer processes utilizing said photosensitive elements.

A further object is to provide novel polymeric compounds.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

* The invention accordingly comprises the several steps and the relation and order of one or more of such steps with respect to each of the others, and the product possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing wherein:

FIGURE 1 is a diagrammatic cross-sectional view of one embodiment of a photosensitive element of this in vention; and

' FIG. 2 is a diagrammatic cross-sectional view of one embodiment of a multilayer photosensitive element within the scope of this invention.

The present invention is particularly related to color diffusion transfer processes. In such processes a photosensitive eement including a silver'halide emulsion layer The latent image is developed and, concurrent with and under the control of this development, an imagewise distribution of mobile color-providing substances is formed. At least a portion of these color-providing substances is transferred by means of an alkaline aqueous processing liquid to a superposed image-receiving layer to form a colored image thereon. As examples of such processes, mention may be made of the processes disclosed and claimed in the copending US. appication of Howard G. Rogers, Serial No. 748,421, filed July 14, 1958 (now US. Patent No. 2,983,606 issued May 9, 1961), as a continuation in part of U.S. application 415,073, filed March 9, 1954 (now abandoned), wherein dye developers (i.e., compounds which contain in the same molecule both the chromophoric system of a dye and also a silver halide developing function) are the color-providing substances, the processes claimed and disclosed in US. Patent No. 2,647,049, issued July 28, 1953, to Edwin H. Land, wherein color deveopers are employed to develop the latent image and color couplers are the color-providing substances, and the processes disclosed in US. Patent No. 2,774,668, issued December 18,- 1956, to Howard G.

Rogers, wherein complete, preformed dyes are used as the color-providing substances. It should be understood that the term color-providing substances as used herein refers to organic materials such as dyes, including dy developers, and dye intermediates.

In an especially useful mode of carrying out color diffusion transfer processes such as described above, the color-providing substances are disposed in a separate alkali-permeable layer in the photosensitive element. The separate alkali-permeable layer may be placed either in front of or behind the photosensitive emulsion with which it is associated; however, in a preferred embodi- Inent it is placed behind, i.e., on the side of the emulsion which is most distant from the photographed subject when the emulsion is exposed, and preferably also adapted to be most distant from the image-receiving element when in superposed relationship therewith. In carrying out the processes, the photosensitive element is exposed and wetted with an aqueous alkaline processing solution, for example, by immersing, coating, spraying, flowing, etc., in the dark, and the photosensitive element is superposed prior to, during or after wetting on an imagereceiving element. In a preferred embodiment the aqueous alkaline processing solution contains a viscosity-increasing compound and is applied to the photosensitive element in a substantially uniform layer as the photosensitive element is brought into superposed position with the image-receiving element. The alkaline aqueous processing solution permeates the photosensitive emulsion and alkali-permeable layers and solubilizes the colorproviding substances to provide a substantially uniform distribution of the color-providing substances therein.

, As the processes proceed, the exposed silver halide image is developed and an imagewise distributionof mobile color-providing substances is formed. At least a portion of the color-providing substances is transferred to and imbibed on the image-receiving element to form the image thereon. The image is viewed'by stripping the image-receiving element from the photosensitive element.

When the color-providing substances are incorporated into a separate alkali-permeab'e layer, it is desirable that said alkali-permeable layer have good dry adhesion to the other layers present in order to withstand the stresses and strains such a layer would be normally subjected to during, for example, coating operations, and especially to withstand the stresses and strains which are encountered if the photosensitive element is a part of a roll film unit. Such adhesion must be achieved in the presence of relatively high amounts of the color-providing substances which generally have little or no adhesiveness in themselves and which often have an adverse effect on the bonding. It is further desirable, and no less important, that said alkali-permeable layer have good wet adhesion to the other layers present; otherwise, during processing, upon stripping the image-receiving element from the photosensitive element, deamination may take place and portions of the photosensitive element would adhere to the surface of the image-receiving element and mar the quality of the transfer image. It is still further desirable that the alkali-permeable layer readily release the color-providing substances in order to make the maximum amount of said materials available for forming the image. In the past, film-forming polymerstsuch, for example, as cellulose acetate hydrogen phthalate have been proposed as materials for the alkali-permeable layers.

It has been discovered that when the color-providing substances are disposed in polymeric layers comprising (A) polymers of N-alkyl-a,B-unsaturated carboxamides and (B) copolymers of N-alkyl-a,;8-unsaturated carboxamides with N-hydroxyalkyl-a, 8-unsaturated carboxamides, such polymers provide wet and dry radhesion which is superior to that obtained with cellulose acetate hydrogen phthalate and, further, said polymers readily release the color-providing substances.

It should be noted that the copolymers of N-alkyl-cz,fiunsaturated carboxamides with N-hydroxyalkyl-a,t3-un saturated carboxamides are novel compounds.

The usefulness of the polymers of this invention is especially demonstrable when dye developers are the color-providing substances. Dye developers, as noted above, are compounds which contain in the same molecule both the chromophoric system of a dye and also a silver halide developing function. By a silver halide developing function is meant a radical which is capable of developing an exposed silver halide image. Particularly useful dye developers are those in which the silver halide developing function is provided by a benzenoid developing radical. A preferred benzenoid developing radical in such compounds is a hydroquinonyl group. Examples of representative dye developers are given in the previously mentioned U.S. application of Howard G. Rogers, Serial No. 748,421. Additional useful dye developers are described in the following copending U.S. applications:

Application Serial No. 449,514, filed August 12, 1954, in the names of Elkan R, Blout, and Myron S. Simon, now abandoned and replaced by continuation-impart application Serial No. 849,727, filed October 30, 1959.

Application Serial No. 471,542, filed November 26 .1954, in the names of Elkan R. Blout, Saul G. Cohen, .Milton Green, Howard G. Rogers, Myron S. Simon and Robert B. Woodward, now abandoned and replaced by .continuation-in-part application Serial No. 1,442, filed January 11, 1960.

, Application Serial No. 478,922, filed December 30, 1954, in the names of Elkan R. Blout, Marilyn R. Cohler, Milton Green, Myron S. Simon and Robert B. Woodward, now abandoned and replaced by continuation-inpart application Serial No. 824,785, filed July 3, 1959.

Application Serial No. 612,045, filed September 25,

1956, in the names of Elkan R. Blout, Milton Green and Howard G. Rogers, now abandoned and replaced by continuation-in-part application Serial No. 144,816, filed October 18, 1961. Application Serial No. 612,052, filed September 25, 1956, in the names of Milton Green and Howard G. Rogers, now abandoned and replaced by continuationin-part application Serial No. 165,930, filed January 12, 1962.

Application Serial No. 612,053, filed September 25, 1956, in the name of Myron S. Simon.

Application Serial No. 612,054, filed September 25, 1956, in the names of Helen P. Husek and Myron S. Simon.

Application Serial 612,055, filed September 25, 1956, in the'name of Helen P. Husek.

Application Serial No. 755,804, filed August 18, 1958, in the names of Elkan R. Blout, Saul G. Cohen, Milton Green and Myron S. Simon.

In color diffusion transfer processes employing dye developers, the dye developer, as mentioned previously for color-providing substances in general, is preferably placed in a separate alkali-permeable layer behind the photosensitive layer. Upon processing the alkaline aqueous processing solution permeates to the separate alkalipermeable layer and solubilizes the dye developer therefrom. As the process proceeds, the latent silver halide image in the photosensitive element is developed, and, as a result of this development, the dye developer in the exposed areas is oxidized and substantially immobilized. At least a portion of the unreacted dye developer is imbibed on a superposed image-receiving element to create thereon the positive dye image. In such processes the immobilization of the dye developers in the exposed areas .is apparently due, at least in part, to a change in the solubility characteristics of the dye developer upon oxiprising the polymers of this invention.

dation. It may also be due in part to a tanning effect on the emulsion by the oxidized developer.

FIG. 1 of the accompanying drawing illustrates one embodiment of a photosensitive element for use in color diffusion transfer processes wherein a polymer within the scope of this invention is used as the material for a separate alkali-permeable layer. The photosensitive element shown therein comprises a support 10, a layer 12 of a N-methylacrylamide N-methylol-acrylamide copolymer containing a color-providing substance and a photosensitive layer 14.

In preparing photosensitive elements of the type mentioned above and in preparing other photosensitive elements within the scope of this invention, the polymeric layers may be conveniently applied from coating solutions containing the desired polymer. The preferred coating solutions comprise 2 to 5% of polymer; however, this amount may be varied to suit particular needs. The coating and drying operations may be carried out according to procedures well known to the art. The color-providing substances which are to be disposed in the separate alkali-permeable layer may be incorporated into the coating solution and applied therewith, or they may be imbibed onto the layer after its application. When the color-providing substances are incorporated into the coating solutions, they may be dispersed so solubilized therein, depending upon the color-providing substance itself, the solvent used and the state desired for the diffusion transfer processes. As examples of suitable solvents which can be used in preparing the coating solutions, mention may be made of water, methanol, ethanol, and methanoltetrahydrofuran mixtures. When the coating solution is applied directly to a support such, for example, as baryta, cellulose acetate, etc., said support may be first subcoated to further enhance the adhesion. When water is used as the solvent for the coating solutions, the color-providing substances, if not soluble therein, may be dispersed directly into the coating solution or they may be first dissolved in an organic, water-immiscible solvent and then dispersed in the coating solution.

The polymers of this invention are also suitable as materials for alkali-permeable layers in integral multilayer photosensitive elements for use in multicolor diffusion transfer processes. As an example of such photosensitive elements, mention may be made of the photosensitive elements disclosed and claimed in the copending U.S. application of Edwin H. Land and Howard G. Rogers, Serial No. 565,135, filed February 13, 1956, wherein at least two selectively sensitized photosensitive strata are superposed on a single support and are processed, simultaneously and without separation, with a single common image receiving element. A suitable arrangement of this type comprises a support carrying a red-sensiitve silver halide emulsion stratum, a green-sensitive silver halide emulsion stratum, and a blue-sensitive silver halide emulsion stratum, said emulsions having associated therewith, respectively, a cyan dye developer, a magneta dye developer and a yellow dye developer. In one of the prefered embodiments of photosensitive elements of this type, the dye developers are disposed in separate alkalipermeable layers behind the photosensitive silver halide emulsion stratum with which they are associated. As in monochromatic photosensitive elements, the polymers of this invention, when used as materials for the alkali permeable layers, provide superior wet and dry adhesion, as compared with cellulose acetate hydrogen phthalate, and also readily release the color-providing substances. When the polymers of this invention are used in such multicolor film units, at least one and usually all the color-providing substances are disposed in layers com- However, it should be understood that in certain instances it may be desirable for reasons such, for example, as permeation rates, transfer rates,"etc., to'dispose some of the coloreral.

providing substances in the silver halide emulsions or in alkali-permeable layers of materials other than those disclosed herein.

A multilayer photosensitive element of the type mentioned above is illustrated in FIG. 2 of the accompanying drawing. A support 20 carries a layer 22 of a N methylacrylamide-N-methylolacrylamide copolymer con: taining a cyan dye developer; a layer 24 of a red-sensitive silver halide emulsion; an interlayer 26, e.g., polyvinyl alcohol, gelatin, etc.; a layer 28 of a N-methylacrylamide-N-methylolacrylamide copolymer containing a magenta dye developer; a layer 30 of a green-sensitive silver halide emulsion; an interlayer 32; a layer 34 of a N-methylacrylamide-N-methylolacrylamide copolymer containing a yellow dye developer; and an outermost layer 36 of a blue-sensitive silver halide emulsion. In certain instances, for example, when the yellow dye developer is not present in a state capable of functioning as a filter, a yellow filter is placed in spacer layer 32.

Although the polymer layers in the photosensitive element of FIG. 2 are shown principally adhered to gelatin or polyvinyl alcohol layers, it should be noted that the polymers of this invention show good adhesion to bydrophilic, alkali-permeable film-forming materials in gen- As a result of this, wide discretion may be exercised in selecting film-forming materials as carries for the silver halide emulsion, interlayers, and other layers which may be adjacent to the polymer layers. For example, one may replace gelatin, which is the carrier usually used in the silver halide emulsion layers, in whole or in part, with gelatin substitutes such, for example, as cellulose ethers, polyvinyl alcohols, partially hydrolyzed organic esters of polyvinyl alcohols, acetals of polyvinyl alcohols, etc. Similar discretion may be exercised in selecting the film-forming materials for the interlayers and other layers. In certain instances, if desired, the polymers of this invention may be used as the interlayers and in other layers which may be present.

Although the polymers of this invention provide good adhesion in and by themselves, in certain instances their adhesion to adjacent layers may be enhanced by incorporating a small amount of said polymers into the layers to which they are to be adhered. The amount of polymer so incorporated may be varied to suit particular needs; generally, however, an amount comprising about by weight, of the adjacent carrier material will provide the increased adhesion.

Both the monochromatic and multicolor photosensitive elements within the scope of this invention may be used in roll films which contain a plurality of photosensitive frames. The photosensitive elements of this invention are especially useful in composite roll film units intended for use in a Polaroid Land Camera, sold by Polaroid Corporation,'Cambridge 39, Massachusetts, or a similar camera structure such, for example, as the camera forming the subject matter of US. Patent No. 2,435,717, issued to Edwin H. Land on February 10, 1948. In general, suchco-mposite roll film units comprise a photo-sensitive roll, a roll of image-receiving material and a plurality of pods containing an anqueous alkaline processing solution. The rolls and pods are so associated with each other that, upon processing, the photo-sensitive element may be superposed on the image-receiving element and the pods maybe ruptured to spread that aqueous alkaline processing solution between the superposed elements. The nature and construction of the pods used insuch unit are well known to the art. See, for example, U.S. Patents Nos. 2,543,181 and 2,634,886, issued to Edwin H. Land.

The polymers for use in preparing the photosensitive elements of this invention may be prepared by polymerizing N-alkyl-a,B-unsaturated carboxamide monomers or by copolymerizing N-alkyl-a,B-unsaturated carboxamide monomers, with N-hydroxyalkyl-afl-unsaturzited carboxamide monomers. The polymerizations may be catalyzed bon atoms.

and carried out under conditions well known to the art. The preferred monomers for use in the preparation are those which comprise less than six carbon atoms, exclusive of the N-alkyl or N-hydroxyalkyl substituents which may be present. The N-alkyl and N-hydroxalkyl substituents preferably comprise less than five carbon atoms and more preferably comprise less than three car- As examples of monomers useful in'preparing the polymers of this invention, mention may be made of N-methylacrylamide, N-ethylacrylamide, N-tbutylacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N-fi-hydroxyethylacrylamide and N ,B-hydroxyethylmethacrylamide. It should be understood that the term "N-alkyl-a,B-unsaturated carboxamide polymers, as used herein, is intended to cover (a) homopolymers of N-alkyl-a,fl-unsaturated carboxamides, e.g., poly-N- ethylacrylamide, and (b) copolymers and terpolymers of various N-alkyl-u, 8-unsaturated carboxamide monomers with one another, e.g., a coplymer of N-methylacrylamide with N-tbutylacrylamide.

In preparing the N-alkyl-u,[3-unsaturated carboxamide- N-hydroxyalkyl-a, (i-unsaturated carboxamide copolymers, the ratio of the N-alky1-a,B-unsaturated carboxamide monomer to the N hydroxyalkyl a,,8 unsaturated carboxamide monomer used in the preparation may be varied to suit particular needs. It has been found, however, that especially useful copolymers are prepared when said ratio is at least 1 to 1 and more particularly about It will be understood that unless the reaction rates of monomers are about equal, the composition of the copo1ymers produced at different stages of the polymerization will vary. The preferred copolymers for use in this invention are the initial polymers produced.

It has been found that when aqueous coating solutions areused to apply the layers which are to be directly'over the alkali-permeable, hydrophilic layers containing the color-providing substances, the water of such coating solutions sometimes swells and distorts the underlying film. In certain instances, when the photosensitive elements are used in transfer processes, such distortions cause slightly irregular patterns, e.g., waviness to appear in the transfer image. Although such patterns detract only slightly from the good overall photographic properties of the transfer image, it 'is often desirable that they be reduced or substantially eliminated. When the N-alkyl-a,/3-unsaturated carboxamide polymers of this invention are used as the carriers for the color-providing substances and it is desired to increase their water-resistance, a small amount of a N-long chain alkyl-ogfi-unsaturated carboxamide monomer may be used in the polymerization. It will be understood that the amount of N-long chain alkyl monomer used may be varied,

the surface of the hydrophilic polymers which bear the color-providing substances. For example, when copolymers of N-alkyl-ot, 8-unsaturated carboxamides with N- hydroxymethyl-a,fl-11nsaturated carboxamides are used as carrier layers for the color-providing substances, the swelling of such copolymers, in the presence of subsequently applied aqueous coating solutions, can be substantiallyreduced by crosslinking. The crosslinked polymers, although having enhanced resistance to swelling in water, still remain water-permeable, thus enabling the l aqueous processing solutions, which are generally used in the subsequent transfer processes, to permeate such lay- Example 1 gms. of N-methylacrylamide were dissolved in 5 ml.

of carbon tetrachloride containing 0.015 gm. of azobisisobutyronitrile and polymerized, under vacuum, for thirty minutes at 65 C. The polymer precipitated and was purified by dissolving in methanol and precipitation into ether. Upon drying, under vacuum, at 35 C. 3.5 gms. of polymer were obtained. The product was soluble in water, methanol and 2% sodium hydroxide.

Example 2' 5 gms. of N-ethylacrylamide, 5 ml. of carbon tetrachloride and 0.015 gm. of azobisisobutyronitrile were sealed, under vacuum, and, polymerized at 65 C. for thirty minutes. The resulting polymer was dissolved in; methanol, precipitated into ether and dried under vacuum. It was soluble in. methanol, dioxane-methanol, ethanoland. water.

Example 3 12.77' gms. of N-methylacrylamide and 1.68 gms. of N-methylolacrylamid'e (9 to 1 molar ratio) were dissolved in 15 ml. of methanol, containing 0.043 gm. of

azobisisobutyronitrile and polymerized, under vacuum, at 65 C. for one hour. The resulting initial polymer was precipitated into ethyl acetate and purified by two addition precipitations from methanol intoethyl acetate. The polymer was soluble in water.

Example 4' 15.32 gms. of N-methylacrylamide and 3.68 gms. of N-t-octylacrylamide (9 to 1 molar ratio) Were dissolved in 19 ml. of methanol containing 0.057 gm. of azobisisobutyronitrile. The mixture was heated, under vacuum, at 65 C. overnight. More methanol was added to dissolve the polymer, and it was precipitated into ether. It was further purified by precipitation from methanol into ether and dried at 40 C. under vacuum. 17 gms. of dry polymer were obtained which was soluble in methanol and water.

The following nonlimiting examples illustrate the preparation and use of photosensitive elements within the scope of this invention.

Example 5 Percent Sodium carboxymethyl cellulose 5.0 Sodium hydroxide 2.0 l-phenyl-B-pyrazolone 0.6 -nitrobenzirnidazole 0.12

2,5-bis-ethyleneiminohydroquinone 0.4

between said photosensitive element and an image-receiw ing element as said elements were brought into superposed relationship. The image-receiving element comprised a cellulose acetate-coated baryta paper which had been coated with an ethanol solution containing 4% Nylon Type F8 (trade name of E. I. du Pont de Nemours & Co., Wilmington, Delaware, N-methoxymethyl-polyhexamethylene adipamide). After an imbibition period of approximately one minute, the image-receiving element was separated and contained a dense yellow positive dye image of the photographed subject. No signs of wet delamination in the photosensitive element were observed.

Example 6 A photosensitive element was prepared in a manner similar to that employed in Example 5 except that the poly-N-ethylacrylamide polymer, as prepared in Example 2, was employed as the carrier for the dye developer. Upon processing in a manner similar to that employed in Example 5, a dense yellow image was obtained. No signs of wet delamination were observed.

Example 7 A photosensitive element was prepared in a manner similar to that employed in Example 5 except that a N-methylacrylamide-N-methylolacrylamide copolymer, as prepared in Example 3, was employed as the carrier for the-dye developer. Upon processing in a manner similar to that employed in Example 5, a dense yellow image was obtained. No signs of wet delamination in the photosensitive element were observed.

Example 8 A photosensitive element was prepared, as in Example 5, except that the N-methylacrylamide-N-t-octylacrylamide copolymer, prepared in Example 4, was employed as the carrier for the dye developer. Upon processing in a manner similar to that employed in Example 5, a dense yellow transfer image was obtained. of wet delamination were observed.

Example 9 A photosensitive element was made up, as in Example- 7, except that 2 cc. of 0.1% hydrochloric acid was added per 10 cc. of the methanol-tetrahydrofuran coating solution. The addition of the acid appreciably increased the resistance of the resulting layer to the emulsion coating solution which was subsequently applied. Upon processing in a manner similar to that employed in Example 5, a dense yellow image was obtained. No signs of wet delamination were observed.

In the above examples, the dry adhesion of the polymer layers was tested by adhering a strip of an adhesive film of the photosensitive element, stripping it from the element and observing for delamination. Each of the photosensitive elements, prepared in the above examples, was superior to similar photosensitive elements prepared with cellulose acetate hydrogen phthalate as the dye carrier. The dry adhesion was further tested by bending the photosensitive elements over rods of various diameters and examining for delamination. In each instance, the photosensitive elements of this invention could be bent to a sharper angle, than similar elements using cellulose acetate hydrogen phthalate as the carrier, without showing signs of delamination.

As mentioned previously, the polymers of this invention may be used in integral multilayer photosensitive elements such as those disclosed in copending application No. 748,421. As examples of coating solutions which may be used to apply the cyan, magenta and yellow dye developer layers in such elements mention may be made of:

1) A methanol-tetrahydrofuran coating solution (1 to 1, by volume) comprising 5.5% of l,4-bis-[/8-(2',5'- dihydroxyphenyl) isopropylamino] anthraquinone' (a No signs 9 cyan dye developer prepared in a manner similar to that disclosed in the previously mentioned copending application No. 478,922) and 2% of a N-methylacrylamide-N- methylolacrylamide copolymer as prepared in Example 3.

(2) A methanol-tetrahydrofuran coating solution (1 to l, by volume) comprising 3.5% of 2-[p-(2,5-dihydroxyphenethyl) phenylazo] 4 n propoxy 1 naphthol (a magenta dye developer prepared in a manner similar to that disclosed in the previously mentioned copending application No. 612,045) and 2% of a N-methylacrylamide-N-methylolacrylamide copolymers, as prepared in Example 3. i

(3) A methanol-tetrahydrofuran coating solution (1 to 1, by volume) comprising 3% of 1-phenyl-3-N-n- .hexyl carbamyl 4 [p (2,5 dihydroxyphenethyl)- phenylazo]-5-pyrazolone (a yellow dye developer prepared in a manner similar to that disclosed in the previously mentioned copending application No. 615,045) and 2% of a N-methylacrylamide-N-methylolacrylamide copolymer, as prepared in Example 3.

The polymers of this invention are further suitable for use in screen type photosensitive elements such as disclosed in the aforementioned application of Howard G. Rogers, Serial No. 748,421, and also the copending application of Edwin H. Land, Serial No. 448,441, filed August 9, 1954, now US. Patent No. 2,968,554, issued January 17, 1961, wherein at least two selectively sensitized silver halide emulsions are arranged in the form of a screen and the color-providing substances, as in multilayer photosensitive elements, are preferably placed in a separate alkali-permeable layer in back of the photosensitive emulsion with which they are associated.

Since certain changes may be made in the above product and process without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A photosensitive element for diifusion transfer color processes, said element comprising a support bearing at least one silver halide emulsion layer and a polymeric layer contiguous with said silver halide emulsion having a color-providing substance disposed therein, said polymeric layer comprising polymers selected from the group consisting of (A) N-alkyl-a,/3-unsaturated carboxamide homopolymers, (B) copolymers of a first N-alkyl-a,flunsaturated carboxamide monomer with at least a second N-alkyl-u,;3-unsaturated carboxamide monomer, and (C) copolymers of N-a-lkyl-a,B-unsaturated carboxamides with N-hydroxyalkyl-me -unsaturated carboxamides, the carboxamides used to prepare the polymers of said polymeric layer being derivatives of cap-unsaturated aliphatic monocarboxylic acids comprising less than six carbon atoms and the N-alkyland N-hydroxyalkyl-substituents of said carboxamides used to prepare the polymers in said polymeric layer comprising less than five carbon atoms.

2. A photosensitive element as defined in claim 1 wherein said color-providing substance is a dye developer, said dye developer being a compound which is both a silver halide developing agent and a dye.

3. A photosensitive element as defined in claim 1 wherein said polymeric layer is between said support and said silver halide emulsion layer.

4. A photosensitive element as defined in claim 1 wherein said polymeric layer comprises a copolymer of a N-alkyl-a,flunsaturated carboxamide with a N-hydroxyalky1-ot,,B-unsaturated carboxamide.

5. A photosensitive element as defined in claim 4 wherein said N-hydroxyalkyl-u,,B-unsaturated carboxamide is a N-hydroxymethyl-a,fi-unsaturated carboxamide.

6. A photosensitive element as defined in claim 5 wherein said copolymer is crosslinked.

7. A photosensitive element as defined in claim 4' 10 wherein the ratio of N-alkyl-ot,fi-unsaturated carboxamide monomer to N-hydroxyalkyl-a,fl-unsaturated carboxamide monomer used to prepare said copolymer is about 9 to 1.

8. A photosensitive element as defined in claim 1 wherein said polymeric layer comprises a N-alkyl-afiunsaturated carboxamide homopolymer.

9. A photosensitive element as defined in claim 1 wherein a small amount of a N-long chain alkyl-u,fi-unsaturated carboxamide was used in the preparation of said polymers.

10. In a process of forming a photographic image in color wherein the latent image container in an exposed silver halide emulsion layer of a photosensitive element is developed to provide an imagewise distribution of color-providing substances in said emulsion, and said imagewise distribution of color-providing substances is transferred by an aqeuous alkaline processing solution to a superposed image-receiving layer to impart to said image-receiving layer a color-image, the improvement of having the color-providing substance in a polymeric layer behind the silver halide emulsion layer and during processing, permeating said photosensitive element with said aqueous alkaline processing solution and solubilizing said color-providing substance from said polymeric layer, said polymeric layer comprising a polymer selected from the group consisting of (A) N-alkyl-u,;8-unsaturated carboxamide homopolymers, (B) copolymers of a first N-alkylnae-unsaturated carboxamide monomer with at least a second N-alkyl-a,/3-unsaturated carboxamide monomer and (C) copolymers of N-alkyl-a,fi-unsaturated carboxamides with N-hydroxyalkyl-cap-unsaturated carboxamides, the carboxamides used to prepare the polymers of said polymeric layer being derivatives of n p-unsaturated aliphatic monocarboxylic acids comprising less than six carbon atoms and the N-alkyland N-hydroxyalkyl-substituents of said carboxamides used to prepare the polymers in said polymeric layer comprising less than five carbon atoms.

11. In a process of forming transfer images in color which comprises exposing a photosensitive emulsion containing a silver halide emulsion layer in a polymeric layer, said polymeric layer containing a dye developer, said dye developer being a compound which is both a silver halide developing agent and a dye permeating said photosensitive element with an aqueous alkaline processing solution and solubilizing at least a portion of said dye developer from said polymeric layer, developing the latent image in the exposed emulsion in the presence of said dye developer whereby said dye developer is immobilized in the exposed areas but is mobile in unexposed areas, thereby providing an imagewise distribution of mobile dye developer, and transferring at least a portion of said mobile dye developer to a superposed imagereceiving layer to form a positive image, the improvement of having the dye developer in a polymeric layer comprising a polymer selected from the group consisting of (A) N-alkyl-a,fl-unsaturated carboxamide homopolymers, (B) copolymers of a first N-alkyl-a,5-unsaturated carboxamide monomer with at least a second N-alkyl-u,;8- unsaturated carboxamide monomer, and (C) copolymers of N-alkyl-a,fl-unsaturated carboxamides with N-hydroxyallcyl-a,B-unsaturated carboxamides, the carboxamides used to prepare the polymers of said polymeric layer being derivatives of cap-unsaturated aliphatic monocarboxylic acids comprising less than six carbon atoms and the N-alkyl and N-hydroxyalkylsubstituents of said carboxamides used to prepare the polymers in said polymeric layers comprising less than five carbon atoms.

. 12. A process as defined in claim 11 wherein said polymeric layer comprises a copolymer of a N-alkyl-a,j3- unsaturated carboxamide with a N-hydroxyalkyl-u, 3-unsaturated carboxamide. V

13. A process as defined in claim 12 wherein said N- 12 amount of a N-long chain alky1-a,/3-unsaturated carboxamide was used in the preparation of said polymers.

References Cited in the file of this patent UNITED STATES PATENTS 2,508,718 Jones May 23, 1950 2,774,668 Rogers Dec. 18, 1956 2,810,713 Melamed Oct. 22, 1957 2,831,826 Coover et al. Apr. 22, 1958 2,834,676 Stanley et a1 May 13, 1958 2,892,710 Cohler et a1. June 30, 1959,

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,069,263 I December 18, 1962 I Howard C. Haas It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 66, for "devoloped" read developed column 4, line 54, for "red-sensiitve" read redsensitive; column 5, line 59, for "photosensitive" read photosensitive line 60, for "anqueous" read aqueous lines 62 and 63, for "photo-sensitive" read photosensitive line 64, for "that" read the same column 5, line 67, for "unit" read units column 6, line 20, for "coplymer" read copolymer lines 31 and 32, for "reaction rates of monomers" read reaction rates of the monomers column 8, line 54, for "of" read to column 9, line 18', for "615,045" read 612,045

Signed and sealed this 11th day of February 1964.

XSEAL) I ttest:

ERNEST w. 'SWIDER Attesting Officer EDWIN L. REYNOLDS Ac ti ng Commissioner of Patents 

10. IN A PROCESS OF FORMING A PHOTOGRAPHIC IMAGE IN COLOR WHEREIN THE LATENT IMAGE CONTAINER IN AN EXPOSED SILVER HALIDE EMULSION LAYER OF A PHOTOSENSITIVE ELEMENT IS DEVELOPED TO PROVIDE AN IMAGEWISE DISTRIBUTION OF COLOR-PROVIDING SUBSTANCE IN SAID EMULSION, AND SAID IMAGEWISE DISTRIBUTION OF COLOR-PROVIDING SUBSTANCES IS TRANSFERRED BY AN AQUEOUS ALKALINE PROCESSING SOLUTION TO A SUPERPOSED IMAGE-RECEIVING LAYER TO IMPART TO SAID IMAGE-RECEIVING LAYER A COLOR-IMAGE, THE IMPROVEMENT OF HAVING THE COLOR-PROVIDING SUBSTANCE IN A POLYMERIC LAYER BEHIND THE SILVER HALIDE EMULSION LAYER AND DURING PROCESSING, PERMEATING SAID PHOTOSENSITIVE ELEMENT WITH SAID AQUEOUS ALKALINE PROCESSING SOLUTION AND SOLUBILIZING SAID COLOR-PROVIDING SUBSTANCE FROM SAID POLYMERIC LAYER, SAID POLYMERIC LAYER COMPRISING A POLYMER SELECTED FROM THE GROUP CONSISTING OF (A) N-ALKYL-A,B-UNSATURATED CARBOXAMIDE HOMOPOLYMERS, (B) COPOLYMERS OF A FIRST N-ALKYLA,B-UNSATURATED CARBOXAMIDE MONOMER WITH AT LEAST A SECOND N-ALKYL-A,B-UNSATURATED CARBOXAMIDE MONOMER AND (C) COPOLYMERS OF N-ALKYL-A,B-UNSATURATED CARBOXAMIDES WITH N-HYDROXYALKYL-A,B-UNSATURATED CARBOXAMIDES, THE CARBOXAMIDES USED TO PREPARE THE POLYMERS OF SAID POLYMERIC LAYER BEING DERIVATIVES OF A,B-UNSATURATED ALIPHATIC MONOCARBOXYLIC ACIDS COMPRISING LESS THAN SIX CARBON ATOMS AND THE N-ALKYL- AND N-HYDROXYALKYL-SUBSTITUENTS OF SAID CARBOXAMIDES USED TO PREPARE THE POLYMERS IN SAID POLYMERIC LAYER COMPRISING LESS THAN FIVE CARBON ATOMS. 